Cooper S Core plug sealant

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Rolandino
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Cooper S Core plug sealant

Post by Rolandino »

Hi, can anyone help ?
Ive just recently done a full rebuild of my engine and had the block acid dipped, hence all the core plugs were removed,
Fitted the core plugs but now they all leak, even if the engine hasnt been started.
I now have to remove all (4) core plugs and replace them.
They were all the correct size, 41.4mm
Does anyone know what the best sealant is so that they dont leak again ?
Thank you.
Roland
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Re: Cooper S Core plug sealant

Post by Peter Laidler »

I blame brexit for the leaks Roly!!!!! When I did mine the machine shop in Oxford told me to re-seat them using that really thick creamy white gluey stuff used by gas fitters when they cap-off the threaded gas pipes in your house. Did mine by smearing it round the plugs and in the holes and they ain't leaked since the late 80's............ Not even when I changed to waterless!
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Re: Cooper S Core plug sealant

Post by Rubber Sprung »

As an ex gas fitter ,would that have been Boss White sealant ?
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Re: Cooper S Core plug sealant

Post by GraemeC »

I think I used a smear of Loctite thread sealant (not threadlock) - think it was 567 off the top of my head
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Re: Cooper S Core plug sealant

Post by johnv »

this stuff, Roland

https://www.ebay.co.uk/itm/133101975741 ... 3yEALw_wcB

I have some here if you're in a hurry!
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Re: Cooper S Core plug sealant

Post by whistler »

I use a smear of blue hylomar.
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Re: Cooper S Core plug sealant

Post by Spider »

I've only ever used Loctite 243. Yes, it's a thread locker, but it's also a sealant.
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Re: Cooper S Core plug sealant

Post by MiNiKiN »

My weapon of choice for any such application is Loctite 620. It has a greater gap-filling ability than the others.


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Re: Cooper S Core plug sealant

Post by CooperTune »

Just as important as the sealer, prepping the opening goes a long way toward proper installation. Steve (CTR)
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Re: Cooper S Core plug sealant

Post by TECH396 »

Permatex #1 for me.
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Re: Cooper S Core plug sealant

Post by Rolandino »

John, sent you a PM, Pls let me have your postcode! R
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Re: Cooper S Core plug sealant

Post by Rolandino »

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Re: Cooper S Core plug sealant

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Re: Cooper S Core plug sealant

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Re: Cooper S Core plug sealant

Post by Ronnie »

Any quality jointing paste or anaerobic sealer should suffice if the surface is clean and in sound condition, if they leak (which they shouldn't) you could attempt to peen them in. :roll:
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Re: Cooper S Core plug sealant

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Re: Cooper S Core plug sealant

Post by Rolandino »

Xxxxxxx
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